| 摘要 |
<p>A power shear has a pair of parallel frame plates spaced apart to either side of a fixed blade and a movable blade. The movable blade can be displaced past the fixed blade to shear a workpiece extending across the plane and resting on the fixed blade A holddown plate is slidably mounted in rails on one of the frame plates and has a pair of edges guided by the rails and overreached by teeth formed on these rails. These edges of the holddown plate are formed with notches that can be aligned with the teeth to allow removal of the holddown plate in a direction perpendicular to its plane. A positioning spindle threaded through a nut fixed on the one frame plate can have an enlarged head engaged in a T-shaped cutout of the holddown plate so that when the holddown plate is lifted perpendicularly off the frame plate it is also disengaged from the positioning spindle.</p> |
